/*
**		entab.c			- add tabs to a text file
**		by Bruce Momjian (root@candle.pha.pa.us)
**
** src/tools/entab/entab.c
**
**	version 1.3
**
**		tabsize = 4
**
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>

#if defined(WIN32) || defined(__CYGWIN__)
#define PG_BINARY_R "rb"
#else
#define PG_BINARY_R "r"
#endif

#define NUL '\0'

#ifndef TRUE
#define TRUE 1
#endif
#ifndef FALSE
#define FALSE 0
#endif

void halt();

extern char* optarg;
extern int optind;

int main(int argc, char** argv)
{
    int tab_size = 8, min_spaces = 2, protect_quotes = FALSE, del_tabs = FALSE, clip_lines = FALSE, prv_spaces,
        col_in_tab, escaped, nxt_spaces;
    char in_line[BUFSIZ], out_line[BUFSIZ], *src, *dst, quote_char, *cp;
    int ch;
    FILE* in_file = NULL;

    if ((cp = strrchr(argv[0], '/')) != NULL)
        ++cp;
    else
        cp = argv[0];
    if (strcmp(cp, "detab") == 0)
        del_tabs = 1;

    while ((ch = getopt(argc, argv, "cdhqs:t:")) != -1)
        switch (ch) {
            case 'c':
                clip_lines = TRUE;
                break;
            case 'd':
                del_tabs = TRUE;
                break;
            case 'q':
                protect_quotes = TRUE;
                break;
            case 's':
                min_spaces = atoi(optarg);
                break;
            case 't':
                tab_size = atoi(optarg);
                break;
            case 'h':
            case '?':
                halt("USAGE: %s [ -cdqst ] [file ...]\n\
	-c (clip trailing whitespace)\n\
	-d (delete tabs)\n\
	-q (protect quotes)\n\
	-s minimum_spaces\n\
	-t tab_width\n",
                    cp);
                break;

            default:
                break;
        }

    argv += optind;
    argc -= optind;

    do {
        if (argc < 1)
            in_file = stdin;
        else {
            if ((in_file = fopen(*argv, PG_BINARY_R)) == NULL)
                halt("PERROR:  Cannot open file %s\n", argv[0]);
            argv++;
        }

        escaped = FALSE;

        while (fgets(in_line, sizeof(in_line), in_file) != NULL) {
            col_in_tab = 0;
            prv_spaces = 0;
            src = in_line;  /* points to current processed char */
            dst = out_line; /* points to next unallocated char */
            if (escaped == FALSE)
                quote_char = ' ';
            escaped = FALSE;

            while (*src != NUL) {
                col_in_tab++;
                if (quote_char == ' ' && (*src == ' ' || *src == '\t')) {
                    if (*src == '\t') {
                        prv_spaces += tab_size - col_in_tab + 1;
                        col_in_tab = tab_size;
                    } else
                        prv_spaces++;

                    if (col_in_tab == tab_size) {
                        /*
                         * Is the next character going to be a tab? Needed to
                         * do tab replacement in current spot if next char is
                         * going to be a tab, ignoring min_spaces
                         */
                        nxt_spaces = 0;
                        while (1) {
                            if (*(src + nxt_spaces + 1) == NUL ||
                                (*(src + nxt_spaces + 1) != ' ' && *(src + nxt_spaces + 1) != '\t'))
                                break;
                            if (*(src + nxt_spaces + 1) == ' ')
                                ++nxt_spaces;
                            if (*(src + nxt_spaces + 1) == '\t' || nxt_spaces == tab_size) {
                                nxt_spaces = tab_size;
                                break;
                            }
                        }
                        if ((prv_spaces >= min_spaces || nxt_spaces == tab_size) && del_tabs == FALSE) {
                            *(dst++) = '\t';
                            prv_spaces = 0;
                        } else {
                            for (; prv_spaces > 0; prv_spaces--)
                                *(dst++) = ' ';
                        }
                    }
                } else {
                    for (; prv_spaces > 0; prv_spaces--)
                        *(dst++) = ' ';
                    if (*src == '\t') /* only when in quote */
                        col_in_tab = 0;
                    if (*src == '\b')
                        col_in_tab -= 2;
                    if (escaped == FALSE && protect_quotes == TRUE) {
                        if (*src == '\\')
                            escaped = TRUE;
                        if (*src == '"' || *src == '\'')
                            if (quote_char == ' ')
                                quote_char = *src;
                            else if (*src == quote_char)
                                quote_char = ' ';
                    } else if (*src != '\r' && *src != '\n')
                        escaped = FALSE;

                    if ((*src == '\r' || *src == '\n') && quote_char == ' ' && clip_lines == TRUE && escaped == FALSE) {
                        while (dst > out_line && (*(dst - 1) == ' ' || *(dst - 1) == '\t'))
                            dst--;
                        prv_spaces = 0;
                    }
                    *(dst++) = *src;
                }
                col_in_tab %= tab_size;
                ++src;
            }
            /* for cases where the last line of file has no newline */
            if (clip_lines == TRUE && escaped == FALSE) {
                while (dst > out_line && (*(dst - 1) == ' ' || *(dst - 1) == '\t'))
                    dst--;
                prv_spaces = 0;
            }
            for (; prv_spaces > 0; prv_spaces--)
                *(dst++) = ' ';
            *dst = NUL;
            if (fputs(out_line, stdout) == EOF)
                halt("PERROR:  Error writing output.\n");
        }
        if (in_file != stdin)
            fclose(in_file);
    } while (--argc > 0);
    return 0;
}
